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Why Use Animals?Biomedical Research
Non-animal and non-human modelsConsider each of the following models. What are some reasons these models might not provide all the information needed to confirm if a new drug or medical device is safe and effective for us to use?
1. A computer model of how a drug is metabolized in the body2. A human tissue sample to study if a new chemical
causes cancer (is the drug carcinogenic)3. Yeast cells used to check if a new drug is toxic to parts
of a cell
Using AnimalsResearch helps us :
understand how our body functions (physiology) understand diseases that affect us (pathology)
Using Animals
Despite the difference in appearance between humans and animals, we share similar biology.
Mice are around 99% genetically similar to humans.
Animals in Research⦿ Used to learn more about biological systems and
the illnesses that afflict human beings and other animals
⦿ Serve as surrogates for humans in obtaining information that cannot be gained in any other way
⦿ Not ethical to test substances or drugs with unknown and potentially adverse side effects on humans
Using AnimalsEven if we give a new medicine to some human cells, this cannot tell us how it will affect the whole body.
Living animals, most commonly mice, rats and fish, are used to see how a medicine affects a whole body.
We also need to know if the medicine will reach the part of the body it needs to.
Animals can tell us about the toxicity and will also indicate what dosage is necessary for humans.
Animals in Research
ANIMAL SYSTEM/CONDITION
Cats Auditory
Primates Immune
Dogs Cardiovascular
Dogs Endocrine
Mice Aging
Rats Aging
About 25 million animals are used for research each year in the US.About 95% are Mice or RatsAbout 3% are guinea pigs, rabbits, or hamsters0.28% Primates0.25 % Dogs0.08% Cats>1% Other species
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Percentage of Animals
Most animals are bred specifically
Breeding allows scientists to control specific traits in animals.
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Where do we get Animals for Research
The Animal Welfare Act (AWA)permits use of dogs and cats from local shelters but due to restrictive legislation this rarely occurs
Some non endangered species are imported for use in research.
Endangered species such as the chimpanzee are NOT used in research.
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Where do we get Animals for Research
Refinement – Finding ways to make research animals’ lives better. ie: toys for animals or better training for technicians
Reduction – Using less animals, only enough to get good results
Replacement – Using non-animal alternatives whenever possible
Three Rs of Research
Dogs= 67% decrease since 1973Cats=68% decrease since 1973Guinea Pigs=48% decrease since 1973Hamsters=68% decrease since 1973Rabbits=53% decrease since 1973
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Decreasing Animal Use
Researchers also try to use the “lowest” type of animal possible for their experiment – for example: a fish instead of a sheep or a fruit fly instead of a mouse.
Why do you think scientists try to replace animal use? Why use “lower” animals – do you agree with this idea?
What do you think?
What do you think?
TIMELINE ACTIVITY
Become an Expert Exercise
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